It seems that Wiener was lecturing, and skipping – as was his wont – about four out of five steps in every demonstration. At one point he said “And therefore it’s obvious that … ” and wrote a string of symbols on the board. He then started to add “Thus we see …” when some thought brought him up sharp. He stared at he board for a few seconds, said, “Wait! Is that obvious?” stared at the board a while longer, said “Excuse me for a minute,” and left the room.

Twenty-five minutes later Wiener returned, drenched in sweat, with his necktie loosened, his collar unbuttoned, and clutching a sheaf of papers covered in scrawled writing.

Coming once again to the front of the room, he turned to the class, said, “Yes, it was obvious,” and resumed the proof of whatever he’d been proving.

No doubt my first instinct was “obvious” only in that extended sense. Any reader with actual expertise is invited to elucidate the problem.

Comments

I heard a version of this joke at Stanford in the early 1960’s, but it was just a generic math lecturer as I recall, no mention of Wiener. On the other hand, I did attend a talk by Wiener at UCLA in the summer of 1959 – memory plays tricks; maybe someone told me the joke then. [By the way, did he always lecture with his head tilted back and his glasses falling off his nose?]

In a way it would be nice if the technocrats responsible for the mess faced personal consequences, though Russian mob justice is unlikely to be fair. You don’t get the impression the men in suits have thought things through – haircutting the insured depositors was a crazy and destabilizing idea.

With respect to obviousness, Daniel Davies’s “choose your own adventure” style version of saving Cyprus can be informative. It’s basically a decision tree labeled with his estimates of probabilities in game form; obviously, it’s somewhat simplified out of necessity and starts at a point where a lot of important decisions have already been made, but even so it makes you think hard about how obvious any seemingly obvious solutions really are, once you account for the interests of all the actors involved and their possible reactions (whether rational or irrational).

I don’t know if Norbert Wiener ever did that in a lecture, but one of my undergrad physics professors really did. It would’ve been ’86 or ’87.

Not that I’m claiming that’s the origin of the story; it was already an old story by the mid 80s. One possibility is that it’s a sort of obvious thing to do, if you’re a lecturer with the appropriate personality. Another possibility is that it was a deliberate joke, especially at MIT where lots of Wiener stories were going around. Perhaps a combination of the two, but I don’t find the first possibility so implausible. This may be one of those urban legends that happened dozens of times in real life, one where it’s hard to track down to a definite origin not because it never happened but because it was so common.